Golden Gate Yacht Club was pleased to be able to get a midwinter race off on Saturday, as temperatures warmed the sailors who hung around in the sunshine, patiently waiting out a 1:20-hour shoreside postponement. In a gentle northerly, the course for all divisions was an easy reach-reach around Alcatraz, just four miles.

Another unusual sight: the GGYC racers come in for the finish with spinnakers flying on a beam reach, while a Hans Christian 38 cruises through.

On Sunday, Richmond Yacht Club’s Small Boat Midwinters occupied two courses out of the way of shipping: The smaller boats sailed in Keller Cove, just north of the old ferry pier, and between Southampton Shoal and Brooks Island.

Sailors might have wished for more wind, but a high pressure system and little variation in temperature between the coast and the inland valleys kept the breezes light. It was a weekend when some folks in the Bay Area found themselves applying sunscreen to arms and legs for the first time this year.

Buzz Blackett (foreground) and Fred Paxton heel their El Toros to windward on a downwind leg.

On January 23, a 7.9 earthquake pulsed from the Gulf of Alaska, and triggered a tsunami warning in San Francisco Bay in the middle of the night. The alert was canceled about an hour later, but it prompted this letter from reader Ian Tuller:

"There was an alert this morning at 3 a.m. for a possible tsunami starting at 6 a.m. I was anchored overnight in Richardson Bay on my Beneteau First 29 in about 13 feet of water. Until the alert was canceled at 4 a.m., I was racking my brain and Googling like crazy to figure out what I should do. The best I could come up with was to get into much deeper water. What do you and your readers suggest?"

We would like to hear from you about your experiences with tsunami warnings and the going conventional wisdom, which we’ll solicit below. But first, we want to take a moment and consider how much of a threat San Francisco Bay faces from the type of catastrophic tsunamis that have caused such appalling death and destruction in other parts of the world.

Tsunamis are generated by geological faults where one tectonic plate slides under another in a process known as ‘subduction’. During an earthquake along these types of faults, the seafloor moves vertically, causing displacement of water that in turn produces the titanic ripples that become a tsunami.

Because the San Andreas Fault — the most significant Bay Area fissure that runs through the ocean — is a ‘slip-strike’ fault (where the plates are rubbing against each other), there is significantly less displaced ocean in the event of a quake. "Even San Francisco’s infamous 1906 earthquake generated only a 4-inch wave at the Presidio gauge station," reported Bay Curious, a podcast on KQED.

Still, tsunamis can travel across oceans. "Since 1854, more than 71 tsunamis have been recorded in San Francisco Bay. Most were generated by earthquakes in subduction zones near Russia, Japan or Alaska," KQED reported, adding that the most severe tsunami to hit the Bay Area was in 1964, after a 9.2 earthquake jolted Alaska. That tsunami killed 11 people in Crescent City, CA, and "rolled in at just under 4 feet and damaged marinas and private boats in Marin County."

The catastrophic 2011 tsunami that devastated much of Japan pulsed into San Francisco Bay 10 hours later as a one-foot wave, while causing "millions of dollars in damage in Crescent City" and $20 million in damage to Santa Cruz Harbor.

The 2011 Tohoku tsunami trickled into San Francisco’s East Bay 10 hours after a 9.0 undersea earthquake struck the Pacific coast of Japan. Nearly 20,000 people were killed.

But what about San Francisco? According to local scientists, a large-scale (16- to 30-ft) tsunami could theoretically strike the mouth of the Bay. KQED cited Steven Ward, a professor of earth and planetary sciences at UC Santa Cruz, who said the majority of this theoretical wave would first hit Point Reyes and Montara before springing under the Golden Gate. "The wave would fan out into San Francisco Bay. Parts of Crissy Field, Mission Bay and the Marina could see significant flooding, but by the time it reached Treasure Island or the East Bay, the wave would be less than three feet tall. It would probably not even make it to the South Bay."

So that’s the worst case, disaster-movie scenario. But what about a warning like we had on January 23? What would you have done? What have you done in the past? In the event of a warning, is it prudent to immediately seek deeper water (or if you’re not on a boat, higher ground)? Please, let us know what you think.

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On Monday we ran a video of a mysterious Unidentified Floating Object motoring past the St. Francis Yacht Club, entertaining the denizens gathered there for dinner. We hadn’t seen it before and thus posed the question to our readers: What the heck is it?

"There must be a Dr Who gathering in town," writes Ants Uiga of Bodfish. "The Tardis was getting so out of touch." (Ants, by the way, is planning to take a Moore 24 on this year’s Race to Alaska. More on that later.)

Turns out the vessel is a ‘Bubbleboat’. When we saw the video, we thought the UFO looked small, like a remote-controlled device or a robot. Turns out it’s an actual boat. The pilot operates the vessel from inside, using the clear glass bubble on top to see where he’s going and a 20hp outboard motor for propulsion.

What looks like a little floating spaceship crosses the StFYC finish line. (Racers will recognize the A buoy in the background.)

Max Perez of Oakland knew the real story: "The artist is Eric Staller. He also made a VW Bug with similar lights. He has some other art/sculpture/vehicles that are really great as well." See ericstaller.com/urban-ufos/bubbleboat. The vessel is festooned with 594 colored carnival lights that are programmed to put on a show and can be controlled from the vessel’s helm.

Turns out the Bubbleboat is nothing new. Staller built the project in 1986 and brought it out of storage in 2013 after he moved to San Francisco. Giants fans have spotted the Bubbleboat in McCovey Cove during games.

One of our readers called the other day with a ‘hot tip’: He went by his favorite Latitude 38 pickup joint, Western Boat & Tackle on Third Street in San Rafael, where readers have been picking up Latitude for about 40 years, and found the magazines but not the business.